With the development of display technology, the flat panel device, such as Liquid Crystal Display (LCD) possesses advantages of high image quality, power saving, thin body and wide application scope. Thus, it has been widely applied in various consumer electrical products, such as mobile phone, television, personal digital assistant, digital camera, notebook, laptop, and becomes the major display device.
Touch panel provides a new human machine interactive interface. The usage is more direct and with more humanization. Forming a touch control device with combining the touch panel and the flat display device is capable of providing the touch control function to the flat display device. With the fingers, the stylus for inputting, the operation can be more intuitive and easy.
At present, the liquid display panel and touch control panel have been widely applied and accepted, used by the people. Meanwhile, it has replaced the traditional CRTs and physical push button input devices.
The initial touch display devices generally utilize the independent type touch control screen, of which the touch control panel and the liquid crystal display panel are separately manufactured, and then combined with assembly. The touch display device obtained by this manufacture solution is thicker. With the additional glass, thin film, the transmission rate and the contrast of the liquid crystal panel obviously descend, either. Moreover, the manufacture cost is higher because of the separate manufacture. The market competitiveness goes down.
For solving the aforesaid problems, a thinner touch display device with better display effect and low cost is provided and the embedded touch control technology is born. The embedded touch control technology is to combine the touch control panel and the display panel as one, and to merge the function of the touch control panel into the liquid crystal panel to make the liquid crystal panel equipped with functions of display and sensing the touch control inputs at the same time.
The present embedded touch control technology mainly comprises two types: one is that the touch control circuit is on the liquid crystal cell (On Cell), and the other is that the touch control circuit is inside the liquid crystal cell (In Cell). The In Cell type can be further categorized as Pure in Cell and Hybrid In Cell. As shown in FIG. 1, in a present In Cell touch control display device, the red, green, blue color resists R, G, B and the Black Matrix 200 made of metal are located at the inner side of the Color Filter (CF) glass 100. The metal BM is employed as conductive material as being the touch control driving electrode (Transmit, Tx) or the touch control sensing electrode (Receive, Rx) which construct a part of the touch control assembly. The foregoing solution may solve the problems of thick separate type touch control screen, low transmission rate, low contrast and high cost. However, the metal BM contains cadmium and pollutes the environment. Because the BM is conductive, some negative influences happen to the Resistor-Capacitor loading (RC loading) of the entire panel and the BM seems to be gradually abandoned.